Unspecified LISN parameters can cause emissions to appear greater than 10 dB high

Experimental findings of the testing of two different products using FCC/VDE LISNs from several manufacturers are summarized. The initial problem, inconsistent measurement of emissions, was noted on one UUT; while measurement of emissions on another UUT were consistent. Modifying the grounding of LISN VA Hash 2 allowed more reproducible measurements compared to LISNs VC or VD which meet the impedance specifications and had a low internal ground impedance.<
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